Semiconductor IC devices include memory devices and logic devices. The memory devices can be classified into volatile memory devices and non-volatile memory devices. The volatile memory devices may include DRAM devices and SRAM devices, and the non-volatile memory devices may include flash memory devices, phase change memory devices, ferroelectric memory devices and magnetic random access memory (MRAM) devices.
Recently, embedded memory logic devices including the memory devices and the logic device fabricated on a single chip have been widely used. The embedded memory logic devices include memory cells for storing data, peripheral circuits for driving the memory cells and logic circuits for processing the data in the memory cells.
The embedded memory logic devices may include both of the volatile memory cells and the non-volatile memory cells as the memory cells. For example, the memory cells may include both of the SRAM cells and the flash memory cells.
A method of fabricating a semiconductor device including full complementary metal-oxide-semiconductor (CMOS)SRAM cells having a single gate structure and flash memory cells having a stacked gate structure is disclosed in Korean Patent No. 10-0344828 to Suh et al., entitled “Method of Fabricating a Semiconductor Device”. According to Suh et al., methods of forming stacked gate patterns of the flash memory cells with single gate patterns of the SRAM cells are provided. However, control gate electrodes of the stacked gate patterns may not be self-aligned with floating gates thereof.
In addition, a semiconductor device including the flash memory cells having the stacked gate structure and SRAM cells having the single gate structure is disclosed in U.S. Pat. No. 6,406,959 B2 to Prall et al., entitled “Method of Forming Flash Memory, Method of Forming Flash Memory and SRAM Circuitry, and Etching Methods”.